Effective Efficiency

[hunter24605]

Can someone help me understand. Maybe it’s how it’s worded, but I can’t wrap my head around it. I think what it is is a measure of how much energy is unused when the bullet exits the muzzle. Second question is, what is acceptable? I’m assuming the higher the better because when you increase barrel length the % goes up. I usually end up with somewhere between 25%~30% what’s confusing me is it’s calling it a ratio, but listed as a percent.
Effective efficiency:
The ratio of the kinetic energy contained at the muzzle in the projectile and the theoretically available energy of the powder mass used.

 

[HodgemanAK]

Is this akin to overbore capacity? Basically trying to cram too much powder down the bore to translate the potential energy of the powder into kinetic energy in the projectile.

In general, the bigger the bore and the smaller the powder charge the more kinetic energy ends up in the projectile per grain of powder burned. Some rounds are really quite efficient like the 308WIN. Some of them, like the 26NOS burn gobs of powder for the increases in speed (and kinetic energy).

 

[JD338]

Diminishing returns

JD338

 

[Bruce Mc]

How many variables are included in that ratio in addition to powder burn characteristics?

 

[hunter24605]

How many variables are included in that ratio in addition to powder burn characteristics?

Here's a couple screenshots showing how it changes with just a change in charge weight

 

[Bruce Mc]

That looks cool, but it seems to me that the information obtained is really only valid for that moment. But, I might be missing the usefulness of the information.

 

[Blkram]

Haven't seen this before, but I haven't had exposure to this program as yet.
To a numbers person, geeking out on this tech, seems pretty cool.
At the end of the day, does this percentage value provided make a difference in the real world?
If the load produces the necessary amount of velocity and energy to cleanly penetrate and expand to produce sufficient tissue and nervous system damage/shock for a quick, clean kill, I would consider it effectively efficient! Rate then equals 100% LOL

I know I have looked at the case efficiencies, where I was looking at the grains/fps and grains/ft.lbs of energy, in order to see which load produced the best gains...but I haven't used this to determine which load I will hunt with...I still go by the load that produces the best accuracy in the given rifle. To me, the confidence in knowing I have an improved chance of placing the bullet accurately and precisely on target that will produce quick, clean kills is most important to me. This means effective and efficient to me.

 

[TackDriver284]

That looks cool, what website is this?

 

[Heavy Barrel]

That looks cool, what website is this?

It's a downloadable platform called Gordons Reloading tool.

 

[RL338]

Effective efficiency:
The ratio of the kinetic energy contained at the muzzle in the projectile and the theoretically available energy of the powder mass used.

I think they add more options to confuse someone.
I like to see burnt propellent near 100% , then I know I’m getting my moneys worth.

 

[noslerpartition]

I guess it means that the powder holds a certain amount of stored energy (It is checked with a calorimeter or similar.)
That stored energy is transformed into heat and movement (bullet, gas,powder)
I guess the ratio shows how much of the energy is transformed into movement of the bullet.

 

[TexasLife]

Are you asking about "ballistic efficiency" numbers? If so what I've noticed is a correlation of unburnt powder, chamber pressure and exit pressure. Efficiency goes up when exit pressure goes down, well on QL anyways. Not always charge weight, but burn rate of powder used. Hope that helps!

 

[TexasLife]

Also watch for in relation to barrel velocity per inch or less. Notice if it's slowing down due to muzzle pressure. Efficiency numbers don't show that.

 

[xphunter]

That makes my brain hurt

 

[noslerpartition]

That makes my brain hurt

Then just ignore it ;-)

 

[salmonchaser]

My guess is understanding all that stuff is what gave us cartridges like the 375 and 416 ruger, or the short mags.

 

[wbm43]

The Truth About Ballistic Efficiency - RifleShooter

Ballisticians and rifle cranks love the word " ballistic efficiency," and it's become a common part

www.rifleshootermag.com

Years ago, Precision Shooting Magazine did a great cartridge efficiency issue. Using their stated definition of "efficiency" among the cartridges tested the winner was the 35 Whelen.